Amended the plan slightly now as I intend to go to Iglesia Santiago y San Juan Bautista from the airport for the formal start of the camino then head about 8km out from Madrid to my first night’s accom which reduces the next day’s distance to about 27km to Colmenar Viejo. Next day will then be about 35km to Cercedilla. Then off to Segovia which is about 30kms. After that I will see how things feel!